package cxt.com.recyclerview.demo1;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v4.view.ViewCompat;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;

/**
 * 作者：chengxiangtong on 2017/1/9 14:46
 * 邮箱：528440900@qq.com
 */

public class DividerItemDecoration extends RecyclerView.ItemDecoration {

    public static final int[] ATTR = new int[]{
            android.R.attr.listDivider
    };

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

    private Drawable mDivider;
    private int mDecorationOrientation;

    DividerItemDecoration(Context mContext, int mOrientation) {
        TypedArray mTypedArray = mContext.obtainStyledAttributes(ATTR);
        mDivider = mTypedArray.getDrawable(0);
        mTypedArray.recycle();

        setOrientation(mOrientation);
    }


    public void setmDivider(Drawable mDrawable) {
        this.mDivider = mDrawable;
    }

    private void setOrientation(int orientation) {
        if (orientation != LinearLayoutManager.HORIZONTAL && orientation != LinearLayoutManager.VERTICAL) {
            throw new IllegalArgumentException("invalid orientation");
        }
        this.mDecorationOrientation = orientation;
    }

    /**
     * 画横竖分割线
     *
     * @param c
     * @param parent
     * @param state
     */
    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
        if (mDecorationOrientation == HORIZONTAL_LIST) {
            drawHorizontal(c, parent);
        } else {
            drawVertical(c, parent);
        }
    }

    private void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();
        final int childCount = parent.getChildCount();

        /**
         * 画每个item的分割线
         */
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int left = child.getRight() + params.rightMargin + Math.round(ViewCompat.getTranslationX(child));
            final int right = left + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    private void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();
        final int childCount = parent.getChildCount();

        /**
         * 画每个item的分割线
         */
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin + Math.round(ViewCompat.getTranslationY(child));
            final int bottom = top + mDivider.getIntrinsicHeight();
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        if (mDecorationOrientation == HORIZONTAL_LIST) {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        } else {
            int position = ((RecyclerView.LayoutParams) view.getLayoutParams()).getViewLayoutPosition();
            int count = parent.getAdapter().getItemCount();
            if (position < count - 1) {
                outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
            }
        }
    }
}
